1. Field of the Invention
The present invention is generally related to firearms and is more particularly related to ammunition magazines used with firearms.
2. Description of the Related Art
During training exercises, military personnel frequently use blank rounds to replicate a combat situation. Blank rounds are also used by police officers to control crowds during riots and civil disturbances, and by the entertainment industry in movies and stage productions.
In recent years, the military has begun to use non-lethal training rounds for force-on-force training. Each non-lethal training round has a non-lethal projectile that is fired at low velocity. The non-lethal projectiles may include paint or ink that leaves a visible mark on the struck object (e.g., an opposition force soldier who has been shot).
Standard magazines have been used to hold live rounds, blank rounds, and non-lethal training rounds. Unfortunately, using the same standard magazine for holding both live rounds and blank/training rounds can be hazardous if a live round is intermixed with blank/training rounds in the same magazine. Regardless of whether the live rounds are placed in the standard magazine on purpose or by accident, the live rounds may not be visible through the opaque walls of the magazine. For example, a soldier may only see blank rounds on top of the magazine and may not be aware that the standard magazine contains one or more live rounds. The magazine may then be inserted into the magazine well of a firearm, and the live round(s) will be fired in the midst of the blank/training rounds, which may result in injury or death to those in the line of fire
There have been some attempts directed to avoiding the intermixing of live rounds with blank/training rounds. For example, U.S. Pat. No. 4,777,752 to Howard discloses a blank magazine having a structure that is different than the structure of a standard magazine for overcoming the safety disadvantages inherent in the use of standard magazines for force-on-force training exercises. In Howard, the blank magazine has a back wall with an inner surface, and a front wall with an inner surface and a top. The blank magazine structure in Howard prevents a live round from being fed by a bolt of a firearm into the chamber of the firearm. If a live round is inserted into the magazine, the top of the front wall engages the projectile of the live round and a cartridge-retaining lip holds the base of a live round lower than it does for the base of a blank, thereby altering the angle of the live round in the magazine. A shorter blank round is not re-positioned at an angle relative to the axis of movement of the bolt. The different position of the blank round compared to the live round permits the bolt to feed the blank round but prevents the bolt from feeding the live round into the chamber of the firearm.
Although Howard teaches that the bolt will not feed the live round into the chamber, the structure of the Howard magazine still allows a magazine having both live and training rounds loaded therein to be fully inserted into the magazine well of a firearm. This dramatically increases the chances that the live round will be accidently directed into the chamber by the bolt.
Thus, in spite of the above advances, there remains a need for a safety magazine that prevents a magazine containing a live round from being fully inserted into a magazine well of a firearm. There also remains a need for a safety magazine that prevents the loading of live 5.56 mm rounds into an M16 style magazine well of a M16 or M4 rifle.